SOURCE: For a complete edition of Phaedrus with macrons, see the edition by J.H. Drake at GoogleBooks. This is fable 22 in the Perotti Appendix to Phaedrus. For parallel versions, see Perry 550.
READ OUT LOUD. Choose which marked text you prefer to practice with - macrons in verse form, or macrons in prose order, or accent marks in prose order, or focusing on the iambic meter. You will find materials for all of these options below. :-)
VERSE MACRONS. Here is the verse text with macrons (note the short e in haererunt):
Sī quandō in silvīs ursō dēsunt cōpiae,
scopulōsum ad lītus currit et prendēns petram
pilōsa crūra sēnsim dēmittit vadō;
quōrum inter villōs cancrī simul ut haererunt,
in terram adripiēns excutit praedam maris,
ēscāque fruitur passim conlēctā vafer.
Ergō etiam stultīs acuit ingenium famēs.
PROSE MACRONS. Here is the same text with macrons written out in prose word order:
Sī quandō in silvīs cōpiae ursō dēsunt, ad lītus scopulōsum currit et, petram prendēns, crūra pilōsa sēnsim vadō dēmittit; quōrum inter villōs simul ut cancrī haerērunt, in terram adripiēns, maris praedam excutit, et vafer ēscā, passim conlēctā, fruitur. Ergō etiam stultīs famēs ingenium acuit.
STRESS (ACCENT) MARKS. Here is the prose text with accents, plus some color-coding for the words of three or more syllables (blue: penultimate stress; red: antepenultimate stress):
Si quando in silvis cópiae urso desunt, ad litus scopulósum currit et, petram prendens, crura pilósa sensim vado demíttit; quorum inter villos simul ut cancri haerérunt, in terram adrípiens, maris praedam éxcutit, et vafer esca, passim conlécta, frúitur. Ergo étiam stultis fames ingénium ácuit.
IAMBIC METER. Here is the verse text with some color coding to assist in the iambic meter. The disyllabic elements (iambs/spondees) are not marked, but the trisyllabic elements are color-coded: dactyls are red, anapests are purple, and tribrachs are green (as is any proceleusmaticus, although that is a rare creature); for more information, here are some Notes on Iambic Meter.
Sī quan·d~ in sil·vīs ur·sō dē·sunt cō·piae,
scopulō·s~ ad lī·tus cur·rit et· prendēns· petram
pilō·sa crū·ra sēn·sim dē·mittit· vadō;
quōr~ in·ter vil·lōs can·crī simul· ut hae·rerunt,
in ter·r~ adripi·ēns ex·cutit· praedam· maris,
ēscā·que frui·tur pas·sim con·lēctā· vafer.
Erg~ eti·am stul·tīs acu·it in·genium· famēs.
IMAGE. Here is an illustration for the story (image source) showing bears at work:
What follows is an unmarked version of the prose rendering to faciliate word searches:
Si quando in silvis copiae urso desunt, ad litus scopulosum currit et, petram prendens, crura pilosa sensim vado demittit; quorum inter villos simul ut cancri haererunt, in terram adripiens, maris praedam excutit, et vafer esca, passim conlecta, fruitur. Ergo etiam stultis fames ingenium acuit.